James Bay Spillway Empty vs: Full

Environmental concerns aside, the James Bay (Robert-Bourassa) hydro-electric dam is an amazing feat of engineering.

The spillway at Robert-Bourassa dam is called “the giant’s staircase.” The structure is named after its unique shape, which features 10 steps, each 10 metres (32 feet or 3 stories) high and 122 metres (400 feet) wide. Based on that the walls look to be about 100 feet high. The spillway has a discharge capacity of 16,280 cubic metres (4.3 Million gallons) of water per second (which is 7 times the amount of water that goes over the Canadian side of Niagara Falls every second @ 600,000 gallons/sec)

From the Hydro Quebec website